#include <REGX52.H>

void Delay1ms(unsigned int xms)		//@12.000MHz
{
	unsigned char i, j;
	while(xms!=0)
	{
	i = 2;
	j = 239;
	do
	{
		while (--j);
	} while (--i);
	xms--;
	}
}

void main()
{	
	while(1)
	{
		if(P3_1==0)
			{
				Delay1ms(20);
				while(P3_1==0);
				Delay1ms(20);
				
				P2--;
			}
	}
}
	